Generally, tobacco is processed by threshers from its whole leaf form into strips and then into smaller “cut filler” pieces. In this form, tobacco may be made into smoking articles, such as cigarettes, cigars, and the like. Various types of smoking articles are made according to blend formulas from tobacco that is stored and aged and then processed through a final processing phase. This processing phase can include conditioning, casing, cutting, drying, top flavoring, and blending. Once this is done, the raw material is finally ready to be made into the smoking articles. In order to produce a characteristic, homogenous blend of tobacco, different types of tobacco are mixed, or blended, according to precise recipes. Tobacco products are blended and/or stored in a “blend bulk silo.” A “silo,” or “bulker,” is a bin for conveying tobacco products from a source of tobacco, blending and/or storing the tobacco, and conveying the tobacco products to processing stations for manufacturing smoking articles. A bulk silo can be used to handle whole leaf tobacco, tip leaf, “strip” tobacco, stems, cut roll stems, cut filler, and other tobacco products as well.
A typical bulk silo may be a rectangular-shaped, longitudinal bin provided with a shuttle car located over it and apparatus for feeding tobacco onto the car and then into the silo. In a blending apparatus, a portion of the bin is charged by a belt moving in one direction on a shuttle which reciprocates back and forth above the bin. The speed and direction of the belt and shuttle can be controlled so as to discharge the tobacco into the bin in an evenly filled manner. A description of such apparatus and methods of processing tobacco in a blend-bulk silo can be found in U.S. Pat. No. 3,811,585, which is incorporated by reference herein in its entirety.
An example of a tobacco bulk silo is one commonly in use today available commercially from Griffin & Cardwell, Inc., of Louisville, Ky. In such a bulk silo, tobacco is layered onto a conveyor means that is connected to a pair of drive chains. The drive chains include assemblies of links, rollers, bushings, and pins. These drive chain components become defective and ultimately inoperative from normal wear and tear related to duration of use, the load on the chain, and the abrasive effect of tobacco on metal parts.
Chains for such conveyors, as well as for other industrial applications, such as elevators, are available from Webster Industries of Tiffin, Ohio. One type of chain commonly used in automated conveyance systems in tobacco product manufacturing equipment is a “roller chain.” In a roller chain, a whole chain link is configured so as to comprise two paired “half” links. One link, or half, of a matched pair has an inner width wider than the other outer width of the other half link of the pair. As such, the narrower half link can fit inside the wider half link so that the two paired half links can be pivotably attached about a pivot member, such as a pin. Due to this paired configuration of half links, replacements for a defective chain half link are provided only in units of two half links.
To replace an entire continuous loop of conveyor chain due to one (or even a few) defective half link(s) would be expensive. An entire chain can cost as much as $9,000 per chain or more. Chain link replacements for conveyors in manufacturing equipment are generally sold in relatively small volumes, and are thus expensive to make and purchase. For example, replacement of a pair of half links can cost as much as $1,800 or more. In addition, because such replacement units are so costly, it is impractical to maintain a stock of these items. Without a ready supply of chain replacement links, when a half link becomes defective and causes the chain to be inoperable, the likelihood of prolonged down time for the manufacturing equipment is increased until a replacement can be procured.
A conveyor chain in manufacturing equipment may operate effectively at a tension that is slightly loose. In tobacco product manufacturing equipment, such as a bulk silo, the gears that engage and move the conveyor chain may be repositioned to adjust the tension on the chain. The length of a chain half link can vary, and can be in a typical chain, for example, approximately six inches in length. To remove a defective half link would involve removing both the defective half link and its matched pair so that the widths of the remaining adjacent half links would properly mate in order to re-establish the continuous chain linkage. Thus, removing two six inch half links would eliminate approximately 12 inches from the overall chain length. Removing this much length from a chain would make the chain too short to connect back into a continuous loop, even with the length adjustment of the chain being at the minimum position. Thus, even with adjusting the positioning of the chain drive gears, removing a defective chain half link and its matched pair is not a workable solution to chain half link repair needs.
Thus, there is a need to provide a system for repairing a linked chain in manufacturing equipment that is relatively inexpensive and that allows maintaining a supply of such repair links for quick repair of a defective chain link.